metaflac(1)

📦
version 1.5.0 · 8 versions
, in fedora 43, fedora 44, nixpkgs unstable

metaflac — the FLAC metadata glow-up station 💅✨

okay so bestie, meet metaflac, the Free Lossless Audio Codec metadata tool. she is that girl: a command-line program who lists, adds, removes, or edits metadata in one or more FLAC files. manual page one, section one, and honestly? iconic.

✨ NAME ✨

metaflac — program to list, add, remove, or edit metadata in one or more FLAC files.

🎀 SYNOPSIS 🎀

metaflac [ options ] [ operations ] FLACfile ...

💖 DESCRIPTION 💖

Use metaflac to list, add, remove, or edit metadata in one or more FLAC files. You may perform one major operation, or many shorthand operations at a time.

like, one big thing OR a whole bunch of little things, your call, she's flexible 🦋

🌸 GENERAL USAGE 🌸

metaflac is the command-line .flac file metadata editor. You can use it to list the contents of metadata blocks, edit, delete or insert blocks, and manage padding.

metaflac takes a set of "options" (though some are not optional, and yes that's a little unhinged of her) and a set of FLAC files to operate on. There are three kinds of "options":

  • Major operations — these specify a mode of operation, like listing blocks, removing blocks, etc. They come with sub-operations that describe exactly what is to be done.
  • Shorthand operations — convenient synonyms for major operations. For example, there is a shorthand operation --show-sample-rate that shows just the sample rate field from the STREAMINFO metadata block.
  • Global options — these affect all the operations.

All of these are described in the tables below (yes, tables, we're fancy). At least one shorthand or major operation must be supplied — she needs something to do, bestie. You can use multiple shorthand operations to do more than one thing to a file or set of files. Most of the common things to do to metadata have shorthand operations.

As an example, here is how to show the MD5 signatures for a set of three FLAC files:

metaflac --show-md5sum file1.flac file2.flac file3.flac

Another example; this removes all DESCRIPTION and COMMENT tags in a set of FLAC files, and uses the --preserve-modtime global option to keep the FLAC file modification times the same (usually when files are edited the modification time is set to the current time):

metaflac --preserve-modtime --remove-tag=DESCRIPTION --remove-tag=COMMENT file1.flac file2.flac file3.flac

💅 OPTIONS 💅

  • -o filename, --output-name=filename — Output to a new file instead of changing or rewriting the input file. so she makes a copy instead of touching the original, we love a considerate queen
  • --preserve-modtime — Preserve the original modification time in spite of edits. This does nothing when -o or --output-name are specified. ngl she's not gonna preserve anything if you already told her to write somewhere else
  • --with-filename — Prefix each output line with the FLAC file name (the default if more than one FLAC file is specified). This option has no effect for options exporting to a file, like --export-tags-to. it's giving "who said that" energy for every line
  • --no-filename — Do not prefix each output line with the FLAC file name (the default if only one FLAC file is specified).
  • --no-utf8-convert — Do not convert tags from UTF-8 to local charset, or vice versa. This is useful for scripts, and setting tags in situations where the locale is wrong. scripts stay winning fr fr
  • --dont-use-padding — By default metaflac tries to use padding where possible to avoid rewriting the entire file if the metadata size changes. Use this option to tell metaflac to not take advantage of padding this way. she'd rather rewrite the whole thing, no shortcuts, main character behavior

🦋 SHORTHAND OPERATIONS 🦋

okay bestie, this is the big list. every single one, no skips, we're not doing that here 💖
  • --show-md5sum — Show the MD5 signature from the STREAMINFO block.
  • --show-min-blocksize — Show the minimum block size from the STREAMINFO block.
  • --show-max-blocksize — Show the maximum block size from the STREAMINFO block.
  • --show-min-framesize — Show the minimum frame size from the STREAMINFO block.
  • --show-max-framesize — Show the maximum frame size from the STREAMINFO block.
  • --show-sample-rate — Show the sample rate from the STREAMINFO block.
  • --show-channels — Show the number of channels from the STREAMINFO block.
  • --show-bps — Show the # of bits per sample from the STREAMINFO block.
  • --show-total-samples — Show the total # of samples from the STREAMINFO block.
  • --show-vendor-tag — Show the vendor string from the VORBIS_COMMENT block.
  • --show-tag=name — Show all tags where the field name matches name.
  • --show-all-tags — Show all tags. This is an alias for --export-tags-to=-. same energy, different name 💫
  • --remove-tag=name — Remove all tags whose field name is name.
  • --remove-first-tag=name — Remove first tag whose field name is name. just the first one bestie, she's being specific
  • --remove-all-tags — Remove all tags, leaving only the vendor string. it's a full reset, no survivors except the vendor string 💀
  • --remove-all-tags-except=NAME1[=NAME2[=...]] — Remove all tags, except the vendor string and the tag names specified. Tag names must be separated by an = character.
  • --set-tag=field — Add a tag. The field must comply with the Vorbis comment spec, of the form "NAME=VALUE". If there is currently no tag block, one will be created. she'll manifest one for you, no worries
  • --set-tag-from-file=field — Like --set-tag, except the VALUE is a filename whose contents will be read verbatim to set the tag value. Unless --no-utf8-convert is specified, the contents will be converted to UTF-8 from the local charset. This can be used to store a cuesheet in a tag (e.g. --set-tag-from-file="CUESHEET=image.cue").
Do not try to store binary data in tag fields! Use APPLICATION blocks for that. she is literally begging you. binary in a tag field is not the vibe.
  • --import-tags-from=file — Import tags from a file. Use - for stdin. Each line should be of the form NAME=VALUE. Multi-line comments are currently not supported. Specify --remove-all-tags and/or --no-utf8-convert before --import-tags-from if necessary. If FILE is - (stdin), only one FLAC file may be specified. order matters here, put those before, okay?
  • --export-tags-to=file — Export tags to a file. Use - for stdout. Each line will be of the form NAME=VALUE. Specify --no-utf8-convert if necessary.
  • --import-cuesheet-from=file — Import a cuesheet from a file. Use - for stdin. Only one FLAC file may be specified. A seekpoint will be added for each index point in the cuesheet to the SEEKTABLE unless --no-cued-seekpoints is specified.
  • --export-cuesheet-to=file — Export CUESHEET block to a cuesheet file, suitable for use by CD authoring software. Use - for stdout. Only one FLAC file may be specified on the command line. one file. ONE. don't test her
  • --import-picture-from={FILENAME|SPECIFICATION} — Import a picture and store it in a PICTURE metadata block. More than one --import-picture-from command can be specified. Either a filename for the picture file or a more complete specification form can be used. The SPECIFICATION is a string whose parts are separated by | (pipe) characters. Some parts may be left empty to invoke default values. FILENAME is just shorthand for "||||FILENAME". For details on the specification, see the section Picture specification in the flac(1) man page. she's got lore, go read the flac(1) page bestie
  • --export-picture-to=file — Export PICTURE block to a file. Use - for stdout. Only one FLAC file may be specified on the command line. The first PICTURE block will be exported unless --export-picture-to is preceded by a --block-number=# option to specify the exact metadata block to extract. Note that the block number is the one shown by --list.
  • --add-replay-gain — Calculates the title and album gains/peaks of the given FLAC files as if all the files were part of one album, then stores them as FLAC tags. The tags are the same as those used by vorbisgain. Existing ReplayGain tags will be replaced. If only one FLAC file is given, the album and title gains will be the same. Since this operation requires two passes, it is always executed last, after all other operations have been completed and written to disk. All FLAC files specified must have the same resolution, sample rate, and number of channels. Only mono and stereo files are allowed, and the sample rate must be 8, 11.025, 12, 16, 18.9, 22.05, 24, 28, 32, 36, 37.8, 44.1, 48, 56, 64, 72, 75.6, 88.2, 96, 112, 128, 144, 151.2, 176.4, 192, 224, 256, 288, 302.4, 352.8, 384, 448, 512, 576, or 604.8 kHz. that whole list is non-negotiable, she checked twice ✨
  • --scan-replay-gain — Like --add-replay-gain, but only analyzes the files rather than writing them to the tags. just looking, not touching 👀
  • --remove-replay-gain — Removes the ReplayGain tags.
  • --add-seekpoint={#|X|#x|#s} — Add seek points to a SEEKTABLE block. Using #, a seek point at that sample number is added. Using X, a placeholder point is added at the end of a the table. Using #x, # evenly spaced seek points will be added, the first being at sample 0. Using #s, a seekpoint will be added every # seconds (# does not have to be a whole number; it can be, for example, 9.5, meaning a seekpoint every 9.5 seconds). If no SEEKTABLE block exists, one will be created. If one already exists, points will be added to the existing table, and any duplicates will be turned into placeholder points. You may use many --add-seekpoint options; the resulting SEEKTABLE will be the unique-ified union of all such values. Example: --add-seekpoint=100x --add-seekpoint=3.5s will add 100 evenly spaced seekpoints and a seekpoint every 3.5 seconds. unique-ified union, she said what she said 💜
  • --add-padding=length — Add a padding block of the given length (in bytes). The overall length of the new block will be 4 + length; the extra 4 bytes is for the metadata block header.

…and bestie, we are literally not even done yet 💖

💥 MAJOR OPERATIONS 💥

These are the big-girl moves. The ones that actually change stuff. Buckle up bestie 🎀

  • --list — Spills the contents of one or more metadata blocks to stdout, like reading your crush's texts out loud. By default, all metadata blocks get listed in text format. Wanna narrow it down? Use --block-number, --block-type or --except-block-type to switch up the behaviour. ✨
  • --remove — Yeets one or more metadata blocks out of the metadata. Use --block-number, --block-type or --except-block-type to say which blocks are getting the boot. Heads up: if you specify both --block-number and --[except-]block-type, the result is the logical AND of both arguments — so it's gotta match both to get removed. Unless --dont-use-padding is specified, the blocks get replaced with padding. And no, you may not remove the STREAMINFO block. That one is protected. 💅
  • --block-number=#[,#[...]] — An optional comma-separated list of block numbers to display. The first block, the STREAMINFO block, is block 0. Counting starts at zero, always. 🔢
  • --block-type=type[,type[...]]
  • --except-block-type=type[,type[...]] — An optional comma-separated list of block types to be included or ignored with this option. Use only one of --block-type or --except-block-type — pick a lane, babe. The valid block types are: STREAMINFO, PADDING, APPLICATION, SEEKTABLE, VORBIS_COMMENT, PICTURE. 🌈

You can also narrow down which APPLICATION blocks get selected by appending APPLICATION with a colon and the ID of the APPLICATION block, in either ASCII or hexadecimal representation. E.g. APPLICATION:abcd for the APPLICATION block(s) whose textual representation of the 4-byte ID is "abcd", or APPLICATION:0xXXXXXXXX for the APPLICATION block(s) whose hexadecimal big-endian representation of the 4-byte ID is "0xXXXXXXXX". For the example "abcd" above, the hexadecimal equivalent is 0x61626364. iykyk 🧚

  • --application-data-format=hexdump|text — If the application block you're displaying contains binary data but you've got --data-format=text, you can display a hex dump of the application data contents instead by using --application-data-format=hexdump. Problem solved, bestie. 🫶
  • --data-format=binary|binary-headerless|text — For use with --list. By default a human-readable text representation of the data is displayed. You may specify --data-format=binary to dump the raw binary form of each metadata block. Specify --data-format=binary-headerless to omit output of metadata block headers — including the id of APPLICATION metadata blocks. 🔥
  • --append — Insert a metadata block from a file. This must be a binary block as exported with --list --data-format=binary. The insertion point is defined with --block-number=#, and the new block gets added after the given block number. Why? Because it prevents the illegal insertion of a block before the first STREAMINFO block. Also: you may not --append another STREAMINFO block. No cap. 🚫

Fun fact though — it's possible to copy a metadata block from one file to another with this option. Like, watch:

metaflac --list --data-format=binary --block-number=6 file.flac > block

...to export the block, and then import it with:

metaflac --append anotherfile.flac < block

Iconic behaviour, honestly. 💖

  • --remove-all — Remove all metadata blocks (except the STREAMINFO block, obviously, she's not going anywhere) from the metadata. Unless --dont-use-padding is specified, the blocks will be replaced with padding. Total reset energy. 🧹
  • --merge-padding — Merge adjacent PADDING blocks into single blocks. Squish them together, they're a family now. 🎀
  • --sort-padding — Move all PADDING blocks to the end of the metadata and merge them into a single block. One big tidy pile at the back, the way it should be. ✨

🌸 SEE ALSO 🌸

  • flac(1) — her sister, her other half, the whole reason we're here 💜

And that's a wrap on metaflac(1), bestie — this page was living in Version 1.5.0, and honestly? She ate. Now go fix your FLAC metadata, you gorgeous little command-line gremlin. 🦋💅

📦 where this page comes from